Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 010545
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1145 PM CST Sat Nov 30 2013
.SHORT TERM...(Today and Monday)
Beautiful weather in progress over extreme southeast Kansas and
the Missouri Ozarks. Temperatures reached the lower 60s in some
spots, under sunny skies and southerly breezes.
For tonight, we leaned the temperature forecast with the
adjusted MET biased corrected guidance, since it`s been the best
verifying model for the past three nights. This will be an
increase in lows for most areas.
We also think fog will develop along and north of Interstate 44
toward the early morning hours of Sunday. Visibilities could
fall below one mile at times.
Slightly cooler temperatures are expected for Sunday as a weak
frontal system stalls over southern Missouri. An increase in
cloud cover could also facilitate cooler temps in the low to mid
By Monday, southerly winds return while full sunshine is expected.
This will lead to temperatures back into the upper 50s and lower
60s. No precipitation is expected through Monday.
.LONG TERM...(Monday Tonight through Friday)
Before we get too deep into the extended discussion, major
differences between the GFS and the ECMWF were noted in their 12Z
solutions. These differences will have big time ramifications on
wintry precipitation chances toward the end of the week.
Collaboration with the Weather Prediction Center this afternoon,
led to a forecast heavily leaned with the ECMWF. As a matter of
fact, the model diagnostics specialist is completely throwing out
the GFS solution, regarding the structure of the upper trough late
in the week.
Essentially the upper low, currently over northwest Canada, will
sag into the western United States as the week progresses. It is
expected that this feature will dig deeper, and hold back over the
Mountain West for a longer period of time, prior to ejecting it`s
main upper speed max over the Ozarks...after...the cold Arctic air
surges through southern Missouri.
This solution will greatly increase the chances for accumulating
wintry precipitation over the entire extreme southeast Kansas and
Missouri Ozarks Region Thursday night into Friday.
At this point, we are still 6 and 7 days out, so we will not get
cute with pinpointing precipitation types and amounts. However, we
have decided to mention a risk for accumulating wintry
precipitation into the Hazardous Weather Outlook.
If you follow the GFS, no wintry precipitation occurs, due to the
model progressing the Canadian low, and shearing it out too fast
through the work week. Again, this is not the recommended solution
to lean next week`s forecast on.
Stay tuned for further updates regarding the possibility of wintry
weather late in the upcoming work week.
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1112 PM CST SAT NOV 30 2013
For the KSGF/KJLN/KBBG tafs: A weak diffuse sfc trough will move
into the area over the next few hours with weak/light winds. Higher
dew points are already in place, and with light winds we expect
dense fog to develop in some areas. Progged soundings and SREF
ceiling (cigs)/visibility (vis) probabilities indicate a good chance
ifr or lifr conditions after 09z, especially at KSGF and KJLN. Low end
vfr/mvfr ceilings/clouds have developed over some areas over
southern MO, possibly complicating the potential for radiation fog
development, especially for KBBG. For now, will continue to be
fairly pessimistic for flight cats given the influx of low level
moisture and weak winds. Clouds may be slow to clear given the
continued weak winds and low sun angles, but there should be
fairly rapid improvement in cigs/vis toward 17z-18z given the
relative shallow depth of the nighttime inversion. Fog may again
develop Sunday night, but mainly after this taf period.